You just got a new laptop — or you're about to accept a refurbished one — and you want to know whether the screen is perfect before your return window closes. Smart move. Dead pixels don't always show up during normal use. They hide in corners, blend into dark backgrounds, or only appear on specific colors.
This guide walks you through a complete laptop pixel test in about two minutes, with nothing to download. Works on Windows, Mac, and Chromebook.
Why You Should Test During the Return Window
Most laptop manufacturers and retailers give you 14–30 days to return a product "no questions asked." After that window closes, you're dealing with warranty terms instead — and warranty coverage for dead pixels is much more restrictive.
Under ISO 13406-2 (the industry standard for display defect tolerance), a Class II monitor — which covers most laptops — can have up to 2 permanently dead pixels, 2 stuck bright pixels, and 5 stuck colored subpixels before it's considered defective. That means one or two bad pixels usually won't qualify for a warranty replacement unless you bought from a retailer or brand with a zero-dead-pixel policy.
During the return window, the rules are different: most major retailers (Amazon, Best Buy, B&H) will exchange a unit with any defect, no pixel-count threshold required. Test now, while you still have options.
Step-by-Step: How to Run a Laptop Dead Pixel Test
You don't need any software installed. Just a browser.
Step 1 — Open the Dead Pixel Test Tool
On your laptop, go to deadpixelcheck.com. Our tool works entirely in the browser — no plugins, no downloads. It generates solid color screens in red, green, blue, white, and black, the five colors that reveal different categories of pixel defects.
Step 2 — Enter Full-Screen Mode
This is the most important step. A browser in normal mode only covers part of your screen — and the areas hidden by the taskbar, address bar, or dock won't be tested. You need full-screen:
- Windows: Press F11 to toggle full-screen in Chrome, Edge, or Firefox.
- Mac: Press Ctrl+Cmd+F to enter full-screen in Safari or Chrome. Or go to View → Enter Full Screen.
- Chromebook: Press F11 or the full-screen key (looks like a rectangle with two lines).
- If F11 doesn't work: In Chrome, click the three-dot menu → More Tools → Full Screen. You can also press F5 on our tool's start screen — it'll switch automatically.
Pro Tip
Close all other applications before testing. Notification bubbles, battery warnings, and background windows can pop up on top of the test screen and look like pixel defects. A clean desktop gives you cleaner results.
Step 3 — Run Through All Five Test Colors
Click or tap anywhere to advance to the next color. Go in order and spend at least 10–15 seconds on each screen:
- Red: Reveals dead pixels (they show as black dots against the red field) and stuck green or blue subpixels.
- Green: Reveals dead pixels and stuck red or blue subpixels.
- Blue: Reveals dead pixels and stuck red or green subpixels. Also reveals backlight bleed in darker corners.
- White: Shows dead pixels (black dots), hot pixels (any color other than white), and uniformity issues (cloudy or grayish areas).
- Black: The most critical test. Reveals bright stuck pixels and backlight bleed. Find a dark corner of your room for this one — ambient light will wash out subtle defects.
Don't skip the black screen
Bright stuck pixels — which show as constant white, red, green, or blue dots — are only visible on the black test screen. Many people skip to the colorful screens and miss stuck bright pixels entirely.
Step 4 — Scan the Entire Display
Don't stare at the center. Move your eyes slowly across the whole screen in a grid pattern — top to bottom, left column to right column. Pay extra attention to the corners and edges, where dead pixels tend to cluster due to pressure during assembly.
If you find something that might be a defect but aren't sure, run a quick sanity check: is the dot consistent across multiple colors? A true dead pixel will appear as a black dot on every color screen. A stuck pixel will appear as the same colored dot on every screen. Dust on the screen will shift or disappear when you wipe the surface with a microfiber cloth.
What You Might Find — and What It Means
Not every dot you see is a dead pixel. Here's how to tell them apart:
| What you see | What it is | Fixable? |
|---|---|---|
| Black dot visible on every color | Dead pixel — transistor has permanently failed | No (screen replacement needed) |
| Bright white, red, green, or blue dot | Stuck pixel — pixel is locked in the "on" position | Sometimes — try pixel fixer |
| Dot disappears when you wipe the screen | Dust, fingerprint, or debris on the surface | Yes — clean the screen |
| Cloudy or grayish area on black screen | Backlight bleed — light leaking around LCD frame | Not really — inherent to LCD design |
| Bright corner glow on black screen | IPS glow — normal optical characteristic of IPS panels | No (not a defect) |
Trying to Fix a Stuck Pixel Before You Return
If what you found is a stuck pixel (colored dot, not a black dot), it's worth trying our built-in stuck pixel fixer tool before heading to the returns counter. The fixer rapidly cycles the stuck pixel through thousands of color changes per second, which can sometimes "unstick" a pixel that's gotten locked in one state.
Run the pixel fixer for 10–20 minutes with the affected pixel centered in the fixer window. Come back afterward and re-run the full color test to see if the pixel has cleared. Success rates vary — some stuck pixels fix in minutes, others never respond.
Run the Dead Pixel Test & Pixel Fixer →What to Do If You Find a Dead Pixel
If you find a true dead pixel (black dot, present on all test colors), your options depend on where you are in the return timeline:
Within the Return Window (Usually 14–30 Days)
Return or exchange immediately. You don't need to cite a pixel count or threshold — you simply don't want the product. Most major retailers handle this with a straightforward exchange. Document the defect with a photo first (use your phone to photograph the laptop screen while displaying a solid color that makes the defect visible).
After the Return Window — Warranty Claim
You're now working with the manufacturer's warranty terms. Key things to know:
- Dell offers a zero-dead-pixel guarantee within the first 30 days on UltraSharp and some XPS models. After that, standard ISO tolerance applies.
- Apple evaluates Retina display defects case by case. With a single dead pixel you may need to escalate — try an Apple Store appointment and ask a Genius to evaluate in person.
- ASUS, Acer, HP, Lenovo generally follow ISO 13406-2 Class 2 standards — one or two dead pixels usually won't qualify for warranty replacement unless you can demonstrate the defect is getting worse or affecting usability.
See our full dead pixel warranty guide for a brand-by-brand breakdown of what each manufacturer will and won't replace.
Testing a Laptop You're Buying Secondhand
Buying a refurbished or used laptop? Run the pixel test before you hand over cash or close the return window on the reseller's platform. Here's a quick checklist:
- Run all five solid-color test screens in full-screen mode
- Test in a dimly lit room — dim light makes subtle defects easier to see
- Check for screen uniformity issues (blotchy areas) in addition to individual bad pixels
- Look for hairline cracks running from the edges — these can cause spreading dead zones over time
- Test the screen at multiple brightness levels (dim screens can hide defects)
Windows-Specific Tips
If you're on a Windows laptop, you have one additional option besides our web tool: the built-in display troubleshooter. Press Win + I → System → Display → and scroll to "Advanced display settings." This won't run a dead pixel test directly, but it can tell you your current resolution and refresh rate — useful for verifying the display is running at its native settings during testing.
Also on Windows: if you notice the defective pixel only shows up at certain angles or only at certain brightness levels, it may be pressure damage rather than a manufacturing defect. Pressure damage occurs when someone presses too hard on the display — it creates spreading dark areas that look like multiple dead pixels but are actually crushed LCD cells. Pressure damage typically isn't covered under warranty.
Mac-Specific Tips
Apple Retina displays use extremely high pixel densities (typically 220–254 PPI on MacBooks), which means individual dead pixels are harder to see with the naked eye — but they're still there. When testing a Retina display:
- Use Safari's full-screen mode (Ctrl+Cmd+F) for the cleanest pixel-for-pixel test
- The display's high DPI means one "display pixel" in the browser may span 2×2 actual hardware pixels — but defects still appear as distinct dots
- On an M-series Mac with ProMotion (120Hz), the display is always at peak quality — no refresh-rate-related anomalies to worry about
Keep Your Laptop Screen in Good Condition
Once you've confirmed your screen is defect-free, keep it that way. The Screen Mom Screen Cleaner Kit includes a streak-free cleaning solution and a microfiber cloth — safe for laptop screens, monitors, and phone displays. It's the cleaner we recommend for regular maintenance.
View Screen Mom Cleaner on Amazon →